The present invention relates in general to hose systems and jackets. More particularly the present invention pertains to a flexible temperature control hose systems.
In many dispensing operations it is necessary to hold the liquid being dispensed at a specific temperature in order to stabilize characteristics such as viscosity. This is generally done with a traditional heat exchanger, often of plate, tube-in-tube or shell-and-tube construction. While reasonably effective in changing the temperature of the material being dispensed, the heat exchanger is traditionally located a distance from the actual point at which the fluid is dispensed. The heat exchanger is generally of a rigid construction and therefore not amenable to use in a motion application. Motion is often required in order to place the fluid in its proper location(s) and this generally results in the use of tubing or hose material to convey the material from the heat exchanger to the moving “gun” or other dispensing apparatus.
As the fluid moves through the tubing or hose, the temperature established in the heat exchanger is influenced by the ambient air surrounding the hose. The magnitude of that influence is directly related to the difference between the outlet temperature of the heat exchanger and the ambient temperature. In general, though the outlet temperature of the heat exchanger may be consistent, ambient temperature values generally vary from morning to evening, resulting in a varying rate of change in temperature.
Tubing insulation is often employed in an attempt to minimize the impact of changes in ambient temperature. However, it is important to note that, while insulation will slow the migration of thermal energy, it will not stop it. This can be addressed to some extent with air conditioning systems to control ambient temperature, but this is both expensive and difficult to implement when the area to be controlled is large (like a factory setting) or the desired material dispensing temperature is significantly above or below the normal human ambient environment of 65° F.-85° F.
In previous applications known to the inventors (Dunning and Cline, et. al., U.S. Pat Nos. 5,287,913 and 5,363,907), the fluid conveying hose is encased in a larger hose and temperature conditioned thermal transfer fluid circulated through the annular space formed between the outside of the inner hose and the inside of the outer hose. This configuration, in essence, creates a flexible tube-in-tube heat exchanger useful for controlling the temperature of the fluid being dispensed.
Some of the most significant issues with this configuration are the means necessary to create the coaxial configuration. These are generally comprised of a series of blocks and connections that transition from the original conveyance to this flexible coaxial configuration. These systems are often bulky and heavy. This is deleterious to both manually and robotically applied systems. Such heavy bulky systems can create fatigue in operators and require added force and energy to accomplish robotic applications. Additionally, the transition from the original conveyance to this flexible coaxial configuration generally involves gaps, threads, or the like which can trap material and create problems with the dispensing system that include, but are not limited to clogged nozzles, contamination, etc. The contamination issue is often significant in this type of system when it is necessary to switch from one material being dispensed to another and the two materials are not chemically compatible. One non-limiting example would be changing from one point to another where contamination between colors or chemistries could significantly alter the quality of the finished product. In such instances it is common practice to change the hoses or tubes conveying the material to eliminate the possibility of contamination. With the aforementioned configuration, the coaxial hose must be changed out or rebuilt, either of which requires significant time and expense.
Thus it would be desirable to provide a system or device to that could provide thermal insulation to hoses and tubing while eliminating or minimizing problems associated with systems employed to date.